[Bug]: the C# client library generator does not use the 'sourceFolder' option when generate the test project code.

Description

The C# client library generator does not use the 'sourceFolder' option when generate the test project code.

Swagger Codegen Version

3.0.81

Language / Generator

csharp

OpenAPI/Swagger Spec

Content of the test.yaml file.

openapi: 3.0.0
info:
  version: "1.0.0"
  title: "Test"
paths:
  /status:
    get:
      operationId: getAssetStatus
      responses:
        "200":
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AssetStatus'
components:
  schemas:
    AssetStatus:
      type: object
      properties:
        live:
          type: boolean
      required:
        - live

Configuration file used

Content of the ConfigCodeGen.json file.

{
  "sourceFolder": "."
}

Command Line Used

java -jar swagger-codegen-cli.jar generate -l csharp -o code -c ConfigCodeGen.json -i test.yaml

Steps to Reproduce

1. Run the generator using the command line specified and the indicated input files.

Expected Behavior

The generator should place the code of the test project in the folder specified through the configuration file as per the IO project.

Actual Behavior

The source code of the test project is place inside the 'src' folder regardless of the configuration.

Environment

• OS: Windows 11;
• Java Version: OpenJDK 26.0.1;
• Build Tool: not builded by myself, I'm using the pre-build version;
• Swagger Codegen CLI version: 3.0.81.

Checklist

• I have searched the existing issues to make sure this is not a duplicate.
• I have included a minimal and reproducible spec example.
• I have explained how to reproduce the issue.
• I have specified which generator/language is affected.

Start by reproducing the command with test.yaml and ConfigCodeGen.json, then inspect how the C# generator chooses the output path for test project code versus the IO project. Done means the configured sourceFolder controls the test project source location instead of always placing it under src.